Prognostic parameters were evaluated in 22 patients with small (less than or equal to 2 cm) superficially invasive (less than 5 mm) squamous cell carcinoma of the vulva. Primary surgery included radical vulvectomy with bilateral superficial and deep inguinal lymph node dissection in 11 patients, and wide local excision with ipsilateral superficial inguinal lymph node dissection in 11 patients. Of the 22 patients studied, only 2 (9%) had lymph node metastases. Both patients had a single positive ipsilateral superficial inguinal node. Perineural invasion was strongly associated with lymph node metastases (P less than 0.01). In this group of patients, grade, depth of invasion, lymph-vascular space invasion, and lymphoplasmacytic infiltration were not predictive of lymph node metastases (P greater than 0.05). Two patients initially treated with wide local excision and ipsilateral superficial inguinal lymph node dissection developed recurrent vulvar neoplasia on the contralateral vulva, and both were successfully retreated by wide local excision. All patients are presently alive and well with no evidence of disease. None of the histomorphologic parameters studied were predictive of tumor recurrence. These data suggest that wide local excision with ipsilateral superficial inguinal lymphadenectomy is effective in the treatment of patients with small, superficially invasive carcinomas of the vulva.